The present invention relates generally to indicating devices and more particularly to an elevator position indicating system which is capable of displaying position information and other information to an occupant of the elevator car.
A prior elevator indicating system, disclosed in Mandel et al. U.S. Pat. No. 3,995,719, includes a position indicator having a display operated in conjunction with an elevator control which detects the position of an elevator car in a hoistway and generates a binary signal representing the position of the elevator car. The binary signals are transmitted to the display located in the elevator car which in turn provides an indication of elevator car location.
One disadvantage of the above-noted system is that the binary signals are sent in parallel form to the display in the elevator car, thereby requiring separate conductors for each bit of the binary signal. This in turn requires a large number of hoistway wires, thereby increasing the cost and complexity of the system.
A further disadvantage is that the elevator control generates a standardized binary signal for each floor of a building regardless of the indication to be generated for that floor, e.g. the elevator control generates a particular signal for the first floor of a building irrespective of whether the display is to indicate a "1" (for the first floor) or "L" (for lobby). This type of system therefore requires that the position indicator be custom programmed so that the position indicator can be used in a particular installation. This programming is in addition to the programming required for the elevator control, thereby requiring customization of both the elevator control and the position indicator and further complicating the task of installing such a system.